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CSV to JSON API

Convert csv files to json with a single POST request. Upload a file as multipart/form-data and the API returns a download URL for the converted file.

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Input

csv

Output

json (application/json)

Credit cost

1 per file

Max file size

Per plan (10–500 MB)

Endpoint

POSThttps://api.fileswitch.co/api/v1/converter/csv-to-json

Authentication is optional for guests and recommended for production. Send either an API key or a JWT access token as a Bearer token. Authenticated requests deduct 1 credit from your balance; failed conversions are refunded. See Authentication for details.

Quick start

The same request in every supported language. Each example uploads a file and prints the downloadUrl from the response.

Example request
curl -X POST https://api.fileswitch.co/api/v1/converter/csv-to-json \
  -H "Authorization: Bearer fc_YOUR_API_KEY" \
  -F "file=@input.csv" \
  -F "delimiter=," \
  -F "prettyPrint=true"

Parameters

Send file plus any optional options. Every option is optional and falls back to its default when omitted.

FieldTypeDefaultDescription
filebinary—The file to convert. Accepts .csv
delimiterstring,

Field separator (single character).

Max length: 1

prettyPrintbooleantrue

Pretty-print the output JSON.

Example request bodyjson
{
  "file": "input.csv",
  "delimiter": ",",
  "prettyPrint": true
}

Response

Every conversion endpoint returns the same success / message / data envelope. The data object is a Conversion record with a temporary downloadUrl.

Response bodyjson
{
  "success": true,
  "message": "Conversion completed",
  "data": {
    "id": "b10a5f2e-8c1e-4b3a-9c1d-2e3f4a5b6c7d",
    "inputFormat": "html",
    "outputFormat": "pdf",
    "inputFileName": "document.html",
    "outputFileName": "document.pdf",
    "inputFileSize": 45210,
    "outputFileSize": 88431,
    "status": "completed",
    "error": null,
    "creditCost": 2,
    "downloadUrl": "/api/v1/converter/download/conversions%2Fb10a5f2e-8c1e-4b3a-9c1d-2e3f4a5b6c7d%2Foutput.pdf",
    "createdAt": "2026-07-31T13:00:00.000Z",
    "completedAt": "2026-07-31T13:00:02.000Z"
  }
}

Prepend https://api.fileswitch.co/api/v1 to the downloadUrl and download with the same credentials. Files are retained temporarily and auto-deleted. See the full field reference in Response Schema.

Related conversions

JSON to CSV

json csv

JSON to XML

json xml

XML to JSON

xml json

XLSX to CSV

xlsx csv

Ready to convert csv → json? Start free — no credit card required.

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